Asphaltic weathering sheet including continuous glass fibers



Jul 25, 1967 J, A. TOMLINSON ETAL ASPHALTIC WEATHERING SHEET mcwnmecommuous GLASS means Filed April 29, 1965 2 Sheets$heet l m m m g R .Bflw 4A6; 7 5 Y W W 4 MO JJ A Ow .1 EL

ASPHALTIC WEATHERING SHEET INCLUDING CONTINUOUS GLASS FIBERS Filed April29, 1963 y 25,1967 J. A. TOMLINSON ETAL 2 Sheets-Sheet 2 INVENTORS254M155 ,4. 70m wso/v,

m MN United States Patent 3,332,830 ASPHALTIC WEATHERIN G SHEETINCLUDING CONTINUOUS GLASS FIBERS James A. Tomlinson, Campbell, Jean A.Berg, San Jose, and John G. Hayes, Campbell, Calif., assignors toOwens-Coming Fiberglas Corporation, a corporation of Delaware Filed Apr.29, 1963, Ser. No. 276,369

9 Claims. (Cl. 161-83) This invention is related to the new roofing andsiding sheet and its manufacture and more particularly to a weatheringsheet made of asphalt reinforced by glass fibers.

In being one of the lowest cost water-proofing materials available,bituminous material such as asphalt has been adopted as a standard bythe roofing industry for incorporation in weathering protection productssuch as roofing, shingles, and siding. Asphalt of itself, however, lackscertain properties of stiffness, wear-resistance, nailholdingproperties, and dimensional stability under conditions of varyingtemperature, so that in order to permit its adaptation for roofing andsiding materials, it must be combined with other materials to compensatefor these deficiencies. To take advantage of the low cost of asphalt,however, materials added thereto to make a practical product must alsobe of low cost, or alternately must be of such character that if higherin cost, they will provide the desired properties with an economicallyincludable amount of the added matter. I

In practice, a low cost base material such as rag felt; including scrappaper, cardboard, mechanical wood pulp, etc. is combined with a low costasphaltic saturant of oillike character which is necessarily of lowviscosity in order to permit impregnation of the felt thereby to formthe carrier base for the product desired. The rag felt base can bespecially treated such as by maceration, but in each instance thesaturant or i-rnpregnant must be of a character which'is adaptable tothe thorough combination with the rag felt. Accordingly, the saturant orimpregnant is usually selected for its ability to saturate the rag feltrather than for its weatherability. A higher viscosity weatheringasphalt layer is thereafter applied in a sense as an icing over thesaturated rag felt base or carrier. The overlying asphalt is selectedspecifically for its weatherability since it acts as the primaryweathering protection for the surface to which the product is applied. Asufficient amount of this material must also be applied to effectivelyprotect the underlying saturated rag felt base against penetration bymoisture. Granules are applied over the thin layer of weathering asphaltto protect it by acting as a sun reflectant and by providing a ruggedsurface against scarring of the Weathering asphalt surface.

Limits on the life of such a product lie both in the thickness of theweathering surface layer applied as well as in the degree of inertnessand dimensional stability of the saturated rag felt base of the product.Since the base saturant for such a product contains a lower viscosityasphalt, generally of a more volatile nature than the exteriorweathering asphalt, and since it is in direct contact with organicmatter of wicking character, the saturant or impregnant has anopportunity to dissipate itself at the product edges, especially withaging, while the wicking properties of the rag felt act to convey theinternally embedded volatile matter to the edges so that eventually thebase or carrier becomes dry and has tendencies to rot. Warping andlifelessness result which permit easy blow-offs of the product underheavy Winds.

In view of the foregoing, it is the principal object of the presentinvention to provide a new low-cost composite asphalt sheet constructionadaptable to roll roofing,

ice

shingles, and siding products, which construction overcomes thedeficiencies of conventional low-cost asphaltic products byincorporating an improved dimensionally stable, fire resistant, longerlife carrier base.

Another object of this invention is to provide a new low-cost moistureprotection, weathering material which is much more fire safe, windresistant, and more weather resistant than products heretoforeavailable.

It is a further object of the invention to provide a new low-costasphalt weathering protection sheet adapted to 7 provide a much morefire safe surface treatment by inclusion of a catalytic compositionwhich promotes a smothering, or in other words, a flame snuffing action,thereby minimizing the tendency for self-sustained combustion andlimiting the flame spread rate of the product.

It is another object of the present invention to provide a new asphaltcomposite weathering sheet including high strength,temperature-resistant matter which will impart dimensional stability tothe sheet to compensate for weakness and flowable nature andaccordingly, low dimensional stability of asphalt in available products,especially under conditions of high temperature to which such productsare subjected in the direct rays of the sun or in emergency situationssuch as during accidental burning of a building structure.

It is still another object of the present invention to provide anasphaltic product for moisture and weather protection which, besidebeing low in cost, has a fire safeness and longevity beyond that ofcorresponding commercially available products.

A still further object of the invention is to provide an asphalticmoisture and weather resistant product which includes a high tensilestrength high modulus reinforcing material having an improved nailtear-resistance permitting its use as protection for buildingstructures, with strength against winds and a degree of stiffness whichminimizes possibilities of blow-off.

In brief, the above objectives are attained according to the presentinvention by providing a construction of two spaced webs of continuousglass fibers irnbedded in a matrix with the core portion interposedbetween the webs. Mineral granules of conventional type deposited overthe weathering surface of the product function as a protection againstthe actinic rays of the sun and provide a more rugged surface towithstand the rigors of installation and subsequent need for loadbearing characteristics.

The continuous glass fibers in the present construction may bedistributed in the spaced webs as individual continuous fibers or intwisted or untwisted strands to impart concentrations of strength in theproduct where desired. In the latter sense, improved nail-holdingproperties can be imparted by concentration of bundles of chopped glassfibers in the zone where nails are passed through to secure theweathering product to the surface to be protected. Concentrations ofglass fibers under the nail heads improve tremendously the tensile andtear strength of the product and, accordingly, its tear-resistance andnailholding properties.

In a broader sense, the present product can be likened to an I-beamstructure with webs of glass fibers spaced apart across the thickness ofthe shingles, siding or roll roofing products. The glass fibers have ahigh tensile strength and high modulus practically independent oftemperature conditions, thereby overcoming a limitation in stiffness ofthe asphalt itself with variations in temperature. Additionally, thespaced web construction with the glass fibers close to the outersurfaces of the product provides a retaining network for asphalt at thesurface and imparts a greater dimensional stability to the surfacematerial than is otherwise possible with the flowable surface ofasphalt. The stability of the asphalt surface is increased by thepresence of the fibers to an extent such that the need for therelatively expensive granules is greatly reduced thereby permitting inmany instances actual elimination of such granules. This occursparticularly with the present structure since the product incorporates aweathering grade asphalt throughout, thus eliminating the need for theextra weathering barrier afforded conventional products incorporatingpaper felt bases by the otherwise thin layer of weathering gradeasphalt. Where the usual surface granules of crushed mineral materialare used, however, the close presence of the network of glass fibersprovides a base or nesting zone for at least a partial nesting withinthe web of the topmost layer of glass fibers, thereby providingadditional protection to prolong the life of the product surface.

Since the spaced mats or webs of glass fibers can be relatively thin andstill provide the additional strength and dimensional stability to theasphalt matrix, the webs can be extremely porous and readily adapted toallowing saturation or passage of the asphalt therethrough. Accordingly,a higher viscosity asphalt such as a weathering grade asphalt can beutilized throughout the thickness of the product so constructed.

In addition to the above, another feature of the invention lies in thefire safeness imparted to the product by its special construction.Conventional asphalt constructions for roofing materials, upon beingsubjected to the heat of a flame extending over a period of a fewminutes, result in a charring of the surface of the asphalt, whichcharred surface of itself is highly fire resistant, but due to theheating and swelling of the substrate below the charred surface, cracksusually occur in the charred surface With a consequent exposure and flowof fresh asphalt for continued spread of flame over the product surface.The present construction however, in providing an inorganicnon-cornbustible network of glass fibers immediately under the topsurface of the product, provide a base for the charred surface whichduring spread of the flames prevents opening of the charred matter.Accordingly, the fire resistance of the charred surface, during exposureto flame becomes progressively more non-combustible, soon results inreduction of the tendency toward sustenance of the flame. Accordingly,if the product surface is the sole base for the flame, it soon causesburn-out, in comparison to continued spread and sustenance of the flamein conventional asphalt products.

A fire safeness of the product of the invention is further enhanced byuse of an asphalt having a residual catalytic reaction dormant in themass as a result of incompletion of the catalytic reaction duringprocessing of the raw asphalt. This dormant reaction is activated ortriggered by exposure to flames which promote a gassing and crusting ofthe asphalt surface to result in snufling out of the flame.

Another feature of the catalyst activated asphalt is that it does notcontain as much oil and consequently does not as readily stain anymineral surface that might be present.

Fire safeness is further enhanced according to the present invention byincorporating concentrations of chopped strands or bundles of fibers ofdiscrete length at the product edges which are critically exposed wheninstalled on a surface to be protected. The presence of a strip or trackembodying concentrations of such fibers assists in reducing flame spreadcharacteristics by plugging up the tendency for flow of asphalt uponheating of the product. That is, When the flame reaches the edge of aconventional shingle structure, studies indicated that the tendency isfor the flame to advance over the edge and then to be retarded or movedback again toward the edge. This is believed due to an initial supportof combustion, but then upon buildup of crust or combustible material,the flame tends to retreat toward the edge of the shingle. Furtherheating of the shingle promotes flow of the asphalt and a subsequentreadvancement of the flame. The readvancing flame again is retarded uponcrusting and buildup of combustibles. In contrast, the presence of thechopped strands in the edge of the product of the present inventionplugs up the tendency for flow of asphalt and thereby reduces or holdsback the readvancement of flame caused by the flow of fresh asphalt.

As a consequence, the flame spread rate of the present product isgreatly reduced by at least three principal mechanisms, namely, 1) theactivation of a dormant catalytic reaction, (2) provision of astabilized rein-forced charred surface with consequent minimization oftendencies toward crackage, and (3) limiting tendencies toward flow offresh asphalt by plugging the exposed edges of the product with choppedlengths of glass fiber strands.

Another feature of the invention lies in the adaptability of the productto construction with a degree of stiffness as desired in accordance withthe use to which it is to be put. For example, if the construction is tobe incorporated in a roofing shingle, a degree of stiffness is desiredto assure that it lays properly on the surface to be protected withoutlikelihood of blow-off. In this regard, it is desired that the productbe sufficiently stiff that when flipped up, it will return to itsnatural position so that subsequent gusts will not in all cases cause itto be lifted again. Furthermore, a strength is desired in the stiffenedproduct to the extent that constant gusting of the product, or in otherWords, a constant flapping of the product, will not result in its beingweakened by working to an extent that it loses its practical protectivevalue. These characteristics are presented in the present product byreason of the adaptability of the construction to being made withdifferent degrees of stiffness, dependent upon the amount of spacingbetween the glass fiber webs incorporated therein. With a wide spacingof the webs, such as with the webs being at their greatest distanceapart at the two major surfaces of the product, the greatest amount ofstiffness is attained. This is particularly desirable in theshingle-type construction when the shingle is of thin dimension. On theother hand, when the product is a roll roofing product, a degree offlexibility is desired which will enable a roll-up for ease of shipmentand ease of installation as Well as case of conformance to the surfaceto be protected. In such instance, the amount of spacing between thewebs can be reduced to provide greater flexibility than might be desiredin the shingle construction. Thus, stiffness or flexibility can beimparted to the construction, dependent upon which is desired.

Products made according to the invention also have a greatly reducedtemperature susceptibility. In the usual case, when the temperature ishigh, the asphalt becomes less stiff and has a tendency to flow, butsince the glass fibers have practically no property variation under theordinary temperatures to which roofing and siding products might besubjected, their incorporation in the asphalt lends greatly tomaintaining stiffness at high temperatures as well as providing greaterdimensional stability.

The fibrous glass webs in a sense also act as retaining membranes forthe asphalt in which they are incorporated. When a rise in temperatureoccurs, even though the matrix material might have a tendency to flow,the inert fibrous glass membranes act as extended lattice networks withinterstices nesting the asphalt near the surface of the product.Accordingly, the degree of flow experienced with products of this typeis reduced to the extent that it might be considered as not occurring atall. Thus, once installed, the roll roofing and shingle typeconstructions of this invention maintain a stable relationship withadjacent abutting and overlapping constructions of similar type and canbe relied upon to have a life much greater than conventional asphalticproducts.

Another and still further feature of the invention lies in theadaptability of the fibrous glass webs to being impregnated with theasphalt, and accordingly permitting selection of asphalt of a coatinggrade and of more fire safe character to be incorporated throughout thethickness of the product. In contrast, if the base or reinforcingmaterial is of low porosity, then the asphalt must be selected for itscapabilities to impregnate or saturate the base or reinforcing material.In the present instance, however, the fibrous glass web need only be ofvery thin dimensions and, accordingly, can be extremely porous and stillprovide the reinforcement and retaining characteristics desired, therebyenabling saturation and coating by a wide range of asphalts notnecessarily selected for their saturating characteristics, but selectedfor their weatherability. Long weathering asphalts generally have a highviscosity and do not economically saturate conventional organic rag feltbase materials. In the present construction, however, the asphaltincorporated in the product can be the same throughout, and thereby forma matrix of high grade weathering material reinforced at the surface bythe glass fiber webs.

V The present product construction is also inherently more adapted toreceipt of granular mineral materials such as crushed rock granules byreason of the presence of the topmost web of glass fibers whichfunctions to stabilize the exposed asphalt surface. In providing theglass fiber webs in the top surface of the product, the

crushed granules can be pressed into the exposed more stable asphaltwith greater assurance of retention, or can be caused to be partiallynested in the glass fiber web. The glass fiber web thus is in a sense alattice network which aids in retention of the crushed rock in positionand provides an additional degree of ruggedness and stabilization notpresent in convention-ally available products.

As pointed out above however, the fact that the glass fibers providesadded surface stability reduces the need for the added protection andexpense afforded by the granules and a more economical product havinglong life properties can be made without such granules.

A still further feature of the invention lies in the adaptability of theconstruction to zonal reinforcement, so that nailing zones can beprovided incorporating additional reinforcing fibers to furtherstrengthen the product against nail tear and blow-off. This isaccomplished in the present invention by providing chopped lengths ofglass fiber strands in the zone of the shingles where nails areconventionally inserted for securernent of the shingle in place againstthe surface to be protected. The chopped strand lengths or bundles ofglass fibers under the nail heads assure proper anchorage of the productagainst the surface to be protected, and an extremely limited likelihoodof tear at the nail zone, in view of the extremely high tensile strengthof such glass fibers.

Another feature of the invention lies in the fact that the relativelyhigh porosity of the reinforcing mat enables use of comparatively higherviscosity mineral filled asphalt of greater fire safe characterthroughout the body of the product. This imparts a higher than usualweather resistance and fire safeness to the product, particularly in thecritical exposed upper and edge regions of the construction. Use of suchhigher viscosity asphalt also permits a greater degree of freedom indesign of flexibility into the product for specific temperature ranges.Additionally, since the matrix of the product is 100% weathering gradeasphalt, early embrittlement and strength loss as well as skidding dueto the usual low softening point of conventional saturants iseliminated.

A further feature of the invention is the particular compatibility ofthe product structure to combination of an asphalt harboring a latentexothermic reaction without need for increasing its viscosity by raisingits temperature to a degree such that the exothermic reaction istriggered. That is, the porosity of the glass fiber web permitsformation of the product with a relatively high viscosity asphalt andtherefore, the temperature of the asphalt need not be raised to a degreewhere the danger of triggering the latent exothermic reaction exists.

The invention will be further described in connection with the drawings,in which:

FIGURE 1 is a partly broken away isometric view of an asphalt shinglereinforced with glass fibers in accordance with the concept of thepresent invention;

FIGURE 2 is a partly broken away enlarged elevational View of theshingle of FIGURE 1;

FIGURE 3 is an illustration of a type of mat or web of glass fibersincorporated in the construction of FIG- URE 1 and illustrating in threedifferent zones three arrangements of glass fibers adaptable toincorporation in such a mat;

FIGURE 4 is a partially broken away side elevational view in perspectiveof apparatus for producing the type of mat illustrated in FIGURE 3;

FIGURE 5 is a schematic isometric view of the method and apparatus bywhich the product of FIGURE 1 is produced;

FIGURE 6 is an enlargement of a portion of the production line of FIGURE5 as taken on line 66; and

FIGURE 7 is a skeletal version of the arrangement of glass fibers in aroofing shingle produced by the method and apparatus of FIGURES 5 and 6.

In greater detail, the shingle 10 of FIGURES 1 and 2 is made of aweathering grade asphalt material 12, physically stabilized by havingcombined therewith a stabilizer such as black slate to improveweatherability and dimensional stability under erosive weatheringforces. The asphalt, it has been found, if of the proper type, cancontribute considerably to the fire safety of the product. In thisrespect, an asphalt is used in accordance with the present inventionwhich is produced by a catalytic air blowing process and retains aresidual or dormant catalytic reaction arising by reason of incompletionof the reaction during processing. In other words, the asphalt is an airblown petroleum residue to which a catalyst has been added. The catalystis added during processing of the asphalt to increase its oxidation rateand accordingly reduce its blowing cycle period. Because of the highviscosity characteristics of asphalt, however, completion of thecatalyzed reaction is ordinarily incomplete. The presence of such anasphalt in the product increases the fire safety of the product in thatwhen it is subjected to the heat of flames, a gassing and a crusting ofthe asphalt surface is promoted when the dormant catalytic reaction istriggered.

An asphalt which has proven successful in providing this fire safety isone catalytically reacted with a chloride type catalyst such as ferricchloride. Phosphorus pentoxide is another example of an asphalt catalystwhich provides an asphalt adapted to the principles of the presentinvention.

The presence of such a catalytic asphalt in the final product isbelieved to cause a foaming at the surface of the product upon contactby flames. The catalyzed asphalt, when contacted by flames attemperatures in the order of 475 F. and higher, produces a violentreaction which acts to halt the spread of such flames. Usually, such anasphalt is held to be undesirable in shingles of conventionalconstruction because its excessively high viscosity at temperaturesunder the reaction triggering temperature, for example 425 F., preventready fabrication of the construction. In the present arrangement,however, such asphalts can be used in view of the porosity of the glassfiber base material which allows permeation by the higher viscosityasphalt at a lower temperature than the triggering temperature whichnormally would be exceeded to accomplish permeation of base materialssuch as rag felt.

Webs or mats 11 and 13 of glass fibers are spaced apart in parallelrelation across the thickness of the construction a distance selectedfor the degree of stiffness desired in the product. As hereinillustrated, the webs are located near the bottom-most and topmostsurfaces of the product and thus produce somewhat of a sandwichconstruction but with the asphalt 12 enclosing both webs in theconstruction while granules 14 of glazed crushed stone or other suitablemineral material are set in the asphalt overlying the topmost layer orweb of glass fibers.

When the overall product dimension is relatively thin, it has been founddesirable that the glass fiber webs 11 and 13 be spaced as far apart aspossible in order to impart the maximum stiffness possible with thegiven components incorporated in the shingle. The usual asphalt, ofitself, lacks the dimensional stability and stiffness desired inshingles to resist the constant force of uniform winds or the erraticaction of gusts of wind blowing thereagainst. Additionally by solocating the webs in the product, the top-most web immediately under theexposed surface of the product ofiters a more stable asphalt surface inwhich the granules 14 can be solidly fixed, thereby improving thecapabilities of the construction to hold the granules in place undervarious weather conditions, as well as assuring a longer life forsurface asphalt against the damaging action of the suns rays and ofwater. The top-most glass fiber mat l1 furthermore acts somewhat as aretainer for the underlying asphalt and consequently is in a sense afire barrier in cases where the product is subjected to hightemperatures such as during a fire occurring in the vicinity of thesurface to be protected. In this way, the uppermost web of glass fiber11, beside acting as reinforcement and as a stabilizing means forsupport of the granules 14, also advantageously stabilizes the asphaltat the surface against motion during emergency conditions experienced inuse. Additionally, since the matrix 12 is of weathering grade andextends throughout the thickness of the construction, life of theproduct against erosion is greatly increased.

The bottom-most glass fiber mat or web 13 acts in conjunction with thetop-most mat 11 to impart strength to the product against its beingripped from the nails used to secure the product to the surface to beprotected. The presence of two layers of glass fibers Within theconstruction, each layer having the glass fibers as high tensilestrength elements extending under the nailheads themselves, providesstrength against pull of the product up and over the nailheads, therebyminimizing the possibilities of tearing of such constructions from thesecuring nails due to wind and the usual forces of the elements. Thebottom-most web, in addition, increases the stiffness of theconstruction as described above and in this respect, it is preferred,especially in a relatively thin shingle construction that the web 13 beas close to the bottom surface as possible so as to assure the maximumspacing from the web 11. This increased stiffness offers resistanceagainst flapping due to the wind. The bottom-most web 13 however,performs an additional function to be described hereinafter in relationto the process by which the product is made.

FIGURE 3 illustrates the type of mat adaptable to incorporation in theconstruction of FIGURE 1. The glass fiber mat 11 includes glass fibersin three different arrangements, namely, glass fibers in the form ofstrands or yarns aligned in relatively straight parallel relationextending along the length of the mat, as well as randomly distributedcontinuous strands or yarns each of a plurality of continuous glassfibers extending over the major dimension of the product. Additionally,discontinuous individual glass fibers are randomly distributedthroughout the major dimension of the product. For tensile strength inthe roofing construction in which the mat is incorporated, thecontinuous strands of glass fibers are most desirable whether randomlyor parallelly oriented in the mat. In both instances, the strands areeither twisted or untwisted, but include a bundle of continuousparallelly aligned glass fibers running for the full length of thestrand. It is well established that individual glass fibers have showntensile strengths up to 1,000,000 lbs. per square inch in laboratorytests and are commercially available with strengths in the order of300,000 to 400,000 lbs. per square inch. Accordingly, bundles of theseindividual glass fibers in the form of strands or yarns incorporated inthe mat impart a high reinforcing strength to matrices in which they areincorporated.

Section A of FIGURE 3 illustrates the appearance of a mat incorporatingthe parallel and random continuous glass strands, as well as thediscontinuous glass fibers utilized to produce the product of FIGURE 1.Regardless of the form in which these mineral fibers are incorporated inthe asphalt, they act as a filler as well as a reinforcing stabilizeragainst thermal and mechanical forces to which the asphalt might besubjected. Section B of FIGURE 2 illustrates the combination ofcontinuous glass fibers in the form of strands and discontinuous glassfibers with the parallel strands omitted. Section C illustrates stillanother section and type of mat which can be utilized successfuily inthe present construction in which both the discontinuous and parallelstrand fibers are omitted. All three sections of FIGURE 3 representtypes of mats which can be incorporated in the roofing constructions ofthis invention, but as herein illustrated and as described in relationto the process by which the product is produced, the type of mat ofSection A incorporating all three forms is preferred. The basicfunctioning elements of the mats of this invention, however, areillustrated in Section C of FIGURE 3.

FIGURE 4 illustrates the method and apparatus by which the mat of thecomposite type including each of the fibrous elements shown in Section Aof FIGURE 3 is produced. In this arrangement, a feeder or bushing 30 isassociated with a source of molten glass, such as the forehearth of amelting tank, and streams of the glass are flowed from tips 31 of thefeeder whereupon the turbulent forces of a set of blowers 32 act onopposite sides of the streams to disrupt them into discontinuous fibers22. The discontinuous fibers 22 move downwardly under the influence ofgravitational forces in addition to the forces of air flowing to thelower pressure zone established below the underlying foraminous conveyor30 on which the fibers are deposited. The fibers are guided downwardlyto the conveyor within a hood 35 surrounding the zone below the blowers32. A separating partition 33 located below the blowers 32 dissects thespace under the blowers so that the fibers 22 are divided into twomoving masses or groups of fibers, namely a front group and a backgroup, which on subsequent deposition on the conveyor 39 form the topand bottom portions respectively of the final mat product.

The separator or partition 33 is a narrow elongated tent-likeconstruction with its apex located in the upper portion of the hood inthe fiber forming zone. The separator provides a space over the conveyorfrom which the continuous glass strands are supplied for deposition onthe conveyor between the bottom and top layer of discontinuous glassfibers. The randomly distributed continuous glass strands 20 are blowninto the separator space from the creel mounted packages (not shown)disposed exteriorly of the hood and are randomly distributed thereinover the underlayer of discontinuous fibers 22, whereupon the mass ismoved forwardly by the conveyor 39 for receipt of the overlayer ofintermingling discontinuous fibers at the forward part of the separatorzone. In the underlying space within the separator the parallel strands21 are also supplied for deposition on the conveyor 30 from tubes 30leading from packages of the continuous strand (not shown) on a creeldisposed laterally at the exterior of the hood 35. These strands areinitially introduced into the mat-forming process by being blown againstthe conveyor 3? whereupon the blowing action is halted and continuedmovement is maintained due to frictional adherence of the strand to themoving conveyor which draws the strands through the tubes 36 rom theirsource located laterally of the hood but not shown herein. Thus, theparallel strands 21 are laid on the conveyor by reason of movement ofthe conveyor while the randomly distributed strands 20 are blown thereonat a linear rate greater than that of the conveyor 39.

To assure that the strands 21 are properly deposited on the conveyor 39without interentanglement in the process 9 of transfer from their sourceto the conveyor, they are arranged to be supplied from side-by-sidealigned tubes 36 located in a separate zone 34 in the back portion ofthe separator 33. The randomly distributed strands 22, on the otherhand, are ejected from the blowing tubes 38 which effect theirdistribution in random arrangement within the wider space of theseparator 33. A wide distribution of the randomly distributed strands 22is efiected by locating the ejecting ends of the tubes 38 some distanceabove the conveyor, which for example may be in the order of 9" to 12"above the conveyor, while the parallel strands 21 which are desirablydeposited in more exactingly spaced relation from each other, aresupplied from the open ends of tubes 36 located Within A" above theconveyor 39.

The entire mass of fibers is supplied with a binding agent from a sourceadjacent to the hood 35 (not shown) and is then conveyed through acuring oven (also not shown) to effect the drying and/ or curing of thebinding agent for full integration of the fibers into the mat. Thebinding agent may be any suitable material preferably a thermosettingagent, having fiber holding properties in temperature ranges above thoseto which the final product is likely to be subjected in use. In thisrespect, phenolic binders, comprising 12% to 25% of the mat, have provensuccessful in having a curing temperature in the range of from 300 to400 F. and the capability of maintaining the interbonded relation forappreciable periods at temperatures in the order of 400 F. Accordingly,the integral relation of the fibers as a retaining member in asphalt orother bitumen materials of the present invention is highly effective forpractically all temperatures to which the product might be subjected innormal usage. The modulus of elasticity of glass fibers is in the orderof from 10 to 12 million, and accordingly, it is highly effective inincreasing the overall stability of the bitumen construction which has amodulus of elasticity a considerable eX- tent lower than the glassfibers.

By way of example rather than limitation of the invention, mats whichhave performed successfully for the purposes of this invention have beenproduced with a thickness of about 10 mils including discontinuousfibers having an average diameter of 60 hundred-thousandths inch and alength of from approximately 3 inches to a few feet, while thecontinuous fibers in bundles or strand-like form comprising about 30% ofthe mat by weight have a nominal diameter of 30 hundred-thousandthsinch. One type of strand commercially available for such purposescontains 204 filaments twisted approximately one turn per inch. Thestrands, however, can be either twisted or untwisted, and in the case ofeither, a dispersion or separation between the filaments within thebundle can be provided to impart a finer texture to the mat and anintermingling interengagement to effect a bridging of the fiber gapsthat might occur across the expanse of the mat. In this respect, strandssuch as described in the Frickert Patent 2,736,676 can be incorporatedin the mat as well as that shown and described in the Frickert et al.Patent 2,875,503. The mat can be made fully of such fiber-dispersedstrands without need for discontinuous fibers if desired. In referringto a strand it is to be recognized that the construction of thisinvention is not limited to untwisted groupings of the continuous glassfibers, but can also be twisted groupings of such fibers, as well astwisted and plied groupings or yarns. The term strand as utilized indescribing the invention is therefore herein meant to refer to each suchform of groupings of glass fibers.

FIGURE 5 shows the apparatus and process by which the roofing materialof the present invention is produced. Although described in relation toproduction of shingles, the process and apparatus is readily adapted toproduction of siding and roll roofing products as well, includingasphalt and other suitable thermoplastic weathering materials.

A flexible glass mat 43 of the type illustrated in FIG- 10 URE 3produced by the method and apparatus of FIG- URE 4 is withdrawn from asupply roll by a pair of feed rolls 50 and is then passed through a pairof coating squeeze rolls 51 and 52 which apply a coating of asphaltthereto for impregnation completely through the thickness of the web ormat. The roll 52 is of dimension such that it dips down into a pool ofmolten asphalt maintained at a predetermined level in a reservoir 53disposed below the web and picks up a quantity of asphalt therefrom forapplication to the underside of the mat 43. A portion of the asphaltpasses through the porous mat and a nip or small globular quantity isformed on the underside of the mat at the bite between the rolls 51 and52, while because of the freedom of the asphalt to pass through theporous mat, a somewhat smaller nip is also formed on the upperside ofthe mat at the bite between the rolls 51 and 52, whereupon continuedmovement of the mat between the rolls causes a squeezing and a meteringof the amount applied to the mat. Although this step in the operationmight be termed a mat coating operation, the asphalt is impregnatedthrough to the upper sides from the underside of the mat. Additionalasphalt can be deposited directly onto the upperside of the mat from asource 55 when desired or necessary to assist in effecting a moreuniform distribution on the upperside of the mat as determined by theflow and penetrating characteristics of the asphalt used. In order toprevent excessive amounts of asphalt from being applied to the undersideof the mat, however, a wiping knife or blade 54 is provided extendingtransversely across the width on the underside of the mat following thesqueezing, coating, and impregnating operation performed by the rolls 51and 52. The blade 54 removes excesses of asphalt from the underside ofthe mat and meters the quantity applied to the underside to the degreedesired. In most instances this mat is desirably provided with a minimumof asphalt on the underside but with a sufiicient amount to cover theglass fibers as protection therefor. Since the catalytic reaction of theasphalt can be triggered at temperatures in the order of 425 F. andhigher, it is stored in reservoir tanks at temperatures in the order of350 F. at which the dormancy of the reaction over extended periods isassured. The asphalt, when ready for use, is then drawn from thereesrvoir tank at temperatures in the order of 400 F.

and flowed to the applicator reservoir 53. The asphalt is maintainedmolten and fluid in the reservoir 53 at a temperature in the order of380 F., at which temperature it is applied to the underside of the mat43.

Upon advancement of the coated and impregnated mat beyond this coatingzone for further processing, it is desired that the mat be cooled. It isa feature of this invention that the bottom reinforcing web or mat iscooled to a degree that molten asphalt subsequently deposited thereonwill not flow through the web by melting the coating and impregnatingmaterial prior to complete assembly of the product. This cooling isaccomplished by first subjecting the impregnated mat to the chillingaction of a coolant such as water supplied by a set of sprays 56 spacedabove and across the width of the mat from which a mist of the coolantis distributed in the zone immediately following the coating operation.The mat is then further cooled and set by air circulated between a pairof air cooling hoods 57 disposed above and below the mat in the zoneimmediately following the spray cooling step prior to its being suppliedwith additional asphalt in a subsequent core forming step. The mist fromthe coolant spray 56 effects an initial chill while the air coolinghoods which extend over a greater length of the path of the mat effectsthe major penetrating and more gradual cooling by circulating air aboveand below the mat.

Upon further advancement of the cooled mat, additional molten asphalt 42is deposited thereon from a metering supply source located above the matin which the asphalt like the asphalt in the reservoir 53, as Well as 1that subsequently applied, is maintained at a temperature in the orderof 380 F. Before the asphalt is applied to the coated mat, however,tracks of discontinuous chopped glass strands are laid on the coated matin the locations 45a, 45b, and 45c (shown in greater detail in FIGURE6), where the longitudinal nailing zones will lie in the final shingles.These nailing zone tracks are in the order of 2 to 3 inches widegenerally near the center of the shingle width, and providereinforcement for the asphalt in these zones to impart nail holdingpower to the product.

Additionally, chopped strands are provided in the locations 46a and 46bof the coated mat corresponding to the major exposed edge of eachshingle subsequently cut from the composite web. The chopped fibers atthe product edges are provided to enhance the fire safety of the shingleby plugging tendencies for flow of asphalt when subjected to the actionof spreading flames.

The chopped strand tracks are made of continuous 60 end glass fiberrovings 47 withdrawn from packages 48 through guide eyelets 49 byconventional rotary type choppers 5801, b, c, d, and e, locatedimmediately above the coated mat in the regions where the respectivetracks 45a, 46a, 45b, 46b, and 450 are to be located. Each roving by wayof example, is made up of 60 continuous glass strands of 204 continuousglass filaments each. When the roving is cut to relatively shortlengths, for example, of l" to 3", it falls into the tracks generally asrandomly distributed chopped strand lengths intermingled to form a massnetwork.

The additional asphalt is thereupon supplied to the coated mat and overthe tracks of chopped glass strands in its fluid condition from asuflicient distance above the mat that it spreads across the width ofthe mat and envelopes the chopped strand tracks to form a core for theproduct as it is advanced. A second mat of glass fibers 41 is drawndownwardly from a source by a pair of squeeze rolls 61 and is applieddirectly over the newly spread asphalt core by passage immediately underthe uppermost squeeze roll 61. The squeeze rolls 61 are disposed adistance apart selected for the thickness desired for the core ofasphalt and are located in a position with respect to the asphalt supply62 such that they act in conjunction with the natural spread of theasphalt to squeeze excesses to the edges of the assembled composite.Excesses squeezed from the edges are deposited in the overflow container65 located under the squeeze rolls 61. The coated mat or web 43 being ina relatively cool, solidified condition is able to withstand the weightof the added molten core asphalt 42 and offers a base arranged by itsmass and degree of cooling such that it does not become sufficientlyheated by the added molten asphalt to allow the core material to flowtherethrough.

The parallel strands in the mat of the present construction improve thetensile strengths of the sheet during processing in production whereineach mat acts as a tensioning element permitting drawing of the sheetthrough the apparatus of the production line. The parallel strandsadditionally act somewhat as a base for bridging of the asphalt acrossthe width of the sheet during the process of assembly of the product.That is, the gaps between the parallelly aligned tensioning strands aresufficiently small that the bitumen matrix deposited thereon acts inbridged or webbed relation across the gaps. The intermingleddiscontinuous fibers are also bridged across the gaps of the parallelstrands, as well as being interbonded in integrated relation across therandomly distributed strands which extend in criss-cross relation aboutthe extended parallel strands. By this means, gaps or voids of fibers inthe mats are minimized while yet providing a porosity permitting,relatively free passage of the fluid bitumen therethrough.

The mat of glass fibers 41, in passing under the top-most squeeze roll61 and acting in compression against the core material on the base webhas an amount of the core asphalt squeezed therethrough so that uponadvancement of the assembly from between the squeeze rolls 61, a thinlayer of asphalt is present over the fibers of the mat 41.

A top overlayer of asphalt is thereupon deposited over the top-most matsupplied from a source 63 located above the assembly in the manner ofthe supply of the core asphalt 62. The material so supplied is spreadover the width of the assembly and is passed between a pair of meteringrolls 64 disposed above and below the assembly a distance justsuflicient to provide the thickness desired to produce a shingleconstruction of predetermined thickness. Excesses of the overlayer ofasphalt are squeezed from the edges of the assembly and into theoversupply container 65 for subsequent recirculation.

A wiping blade 69 is disposed on the underside of the assembly whichmakes contact with the underlayer of asphalt subsequent to passagethrough the metering rolls 64 to wipe any excesses of asphalt that mighthave passed to the underside. The amount of asphalt in the assemblyprior to deposition of additional amounts from the sources 62 and 63respectively, however, are such that upon cooling, the amounts added incombination with the chopped glass strand lengths are arranged to beinsufficient to convey heat to the bottom web to an adequate degree tocause excessive weakening of the lowermost asphalt web reinforced by themat 43, and accordingly, the dripping of asphalt through the web isunlikely. The presence of the blade or wiper 69, therefore, isprecautionary for wiping of excesses squeezed from between the finalmetering rolls 64 in order to assure that the bottom-most mat 63 islocated as close to the bottom of the assembly as possible.

The usual protective and decorative mineral granules such as crushedstone, if to be provided on the product, are thereupon deposited on theupper layer of weathering asphalt exposed after passage through themetering rolls 64. The granules 44 are supplied from a hopper 66 and aremetered over the exposed asphalt surface of the assembly by a flutedfeed roll 67 disposed immediately below a granule supply hopper 66. Amultiple hopper applicator for blended colors can be used as areplacement in this stage of the process if desired. Rotation of thefluted roll 67 is matched to the forward movement of the conveyor lineto assure an even supply of granules over the entire length of theassembly.

The granuled construction of asphalt and glass fibers is then advancedunder and around a driven slating drum 68 which acts to partially setthe granules into the asphalt of the exposed surface upon which they aredeposited, while excesses of the granules which are not therebyadhesively secured to the assembly are dropped into the hopper 66 byreason of the overturned relation of the sheet after passage about theslating drum 68. A parting agent such as mica particles 72 are depositedon the underside of the roofing sheet after passage over the slatingdrum 68. The mica is supplied from a hopper 71 which feeds a quantity ofparticles to a vibrating inclined surface member 70. Although mica isherein described as being used as the parting agent, it will berecognized that any number of materials can be utilized to provide thedesired non-sticking character in the final product. Sand is anothertype of material adapted to use for this purpose.

After supply of the parting agent to the back of the sheet, thecontinuous composite sheet is advanced about a turnover drum 73 whichmore permanently fixes the parting agent to the back of theconstruction. Excesses of the parting agent are wiped from the drum 73by a transverse member 74 and are redeposited on the vibrating surfacemember 70. The final assembly of components for this sandwichconstruction is then advanced through two pairs of press rolls 76 and 77aligned in series for final dimensioning and setting of the granules inthe top-most surface of the construction. After passage through thepress rolls 76, the continuous sheet is passed over a guide roll 78prior to being formed into loops to allow more gradual cooling of thesheet than would otherwise be possible at the speed of production of theconstruction.

After advancing over the guide roll 78, the sheet or composite web ofmaterial is moved into a moving roller conveyor made up of a series ofparallelly aligned slowly advancing rolls 80 extending transverse to thewidth of the sheet. The portion of the sheet in engagement with thesecond roll 80 of the conveyor is pinched between the second roll and apair of stationarily disposed spaced wheels or tires 79 which slows theadvancing movement of the pinched portion and accordingly forms a loopbetween the first and second rolls 80 of the conveyor. Continuedadvancement of the second roll under the wheels or tires 79 advances thenewly formed hanging loop of the composite web past the wheels 7 9placing it in series with the preceding loops on the conveyor line. Inview of the web so being slowed in its linear advancement to subsequentcutting and packaging operations, it is provided an opportunity to coolslowly to a more stable condition for the further processing.

The rate of advancement of the rollers 80 relative to the rate ofadvancement of the sheet during its fabrication determines the length ofthe loops 81, and accordingly, the time allowed for cooling of the webfollowing fabrication.

The relative rates between fabrication and cooling of the web isregulated so that it is fully stabilized upon subsequent slitting,cutting and packaging. At the end of the line of rollers 80, thecomposite web is withdrawn from the last of the series of loops 81 by apair of pulling rolls 82 for feed thereof to a pair of slitter rolls83-. The rate of withdrawal of the web by the pull rolls 82 can beregulated to providea short additional loop 85 before the slitter rolls83, thereby reducing the requirement for an exactingly matched speedrelation between the slitter rolls 83 and the pull rolls 82. Tensionproblems for cutting the sheet are thereby minimized.

The slitter rolls 83 effect a severance of the web into three equalwidths which are retained in side-by-side abutting relationship, inwhich relationship they are drawn through a pair of measuring driverolls 84 for passage to a pair of driven cutting rolls 86 which effect acutting of each of the parallelly moving strips of the web to formshingles of the general shape illustrated in FIGURE 1.

After being cut, the shingles are received by a pair of feed belts 87which supply the shingles into stacked relation on a stacking plate 88on a packaging bed 90 for strapping and final shipment.

By way of further example, successful sheets so produced have had athickness dimension in the order of 125 mils with a spacing between 10mil glass fiber webs in the order of 75 mils. In other words, thedesired stiffness is imparted to the sheet with the spacing between websbeing approximately 60% ofthe sheet thickness and the ratio of spacingto mat thickness being 7.5 to 1. The mats comprise approximately 2 to 4%by weight of the sheet while the core therebetween made up approximately50% by weight of the sheet. Asphalt saturant in the lower mat comprised4% and the top coat asphalt 10% of the product. Surface granules wereabout 32% and parting agent 1.5% of the product weight. The range of matthicknesses can extend at least from 0.005" to 0.05 while spacing can befrom 0.010" to 0.200". Discontinuous fiber diameters can be in the rangeof 0.0001" to 0.002 and continuous fibers from 0.0001" to 0.001. Theweight of the two mats can range from 0.01 to 0.1 lbs. per foot and from1 to 20% of the product weight. Asphalt incorporated therein containing200 mesh stabilizing slate particles or similar suitable mineralmaterial in the order of 50% by weight of the asphalt has been found toprovide excellent stiffening and weathering characteristics.

Tests of asphalt shingles with and without surface granules on theexposed surface have indicated under a given set of conditions ofexposure to the sun, that asphalt which reached a temperature of 125 F.with the granules present, would reach a temperature of F. without thepresence of surface granules. As indicated previously, however, the lackof surface granules can be tolerated in the structure of the presentinvention even though the asphalt might reach a higher temperaturebecause of the stability imparted to the exposed surface due to theglass fiber network of the upper mat adjacent thereto.

Referring again to FIGURES 6 and 7 in the light of the foregoingdescription of the production line, the chopped strand nailing zonetracks 45a, 45b, and 450, spaced across the width of the carrier web 43,are made of 60 end rovings chopped to relatively short lengths forexample, of 2 to 3 inches, and are deposited randomly in a track havinga Width, for example, of approximately 3 inches. The amount of choppedstrands per hundred square feet of shingles can amount to 0.4 pound. Thenailing track 450 is located a distance back from the exposed edgecorresponding to the cut out portions 151 as shown in FIGURE 7. Wherethe shingle width is in the order of 12 inches, the nailing zone 450 canbe 6 inches back from the exposed edge of the shingle. Thus, where 3shingles are cut from the web produced on the production line of FIGURE5, the web would be 36" wide, and accordingly three separate 3" trackswould be provided across its width.

The two additional tracks of chopped strands 46a and 4611 are providedfor the exposed edges of the shingles cut from the web. Only twoadditional tracks are required for the three shingle web, since two ofthe shingle strips have their exposed edges abutting each other in thearrangement of FIGURE 5. In this way, the chopped strand track 46boverlapping the zone where the cut is made to form the abutting exposededges of adjacent shingle strips is 6" wide to provide two marginaledges reinforced by chopped strands. The second track 46a need be onlyas wide as a single track in a shingle since it forms the basis for anailing zone at the marginal edge of only the remaining shingle strip.

As pointed out in the foregoing, the chopped strands at the edge of theshingle assist in reducing flame spread or in other words, provides aflame barrier by plugging up the tendency for flow of asphalt uponheating of the shingle structure. That is, the spread of flame, inaddition to being retarded by kick-off of the dormant catalytic reactionin the asphalt is further retarded by the presence of the choppedstrands or bundles of glass fibers of discrete length at the shingleedge which hold the crusted or combusted materials intact after exposureto flames. The flow of fresh asphalt from the interior of the structurepromoting the continuance and spread of flames is thus prevented. Instill other words, the chopped strands at the shingle edge plug up thetendency for flow of hot asphalt and hold back the flow of asphalt withits consequent tendency toward continued support and advancement offlames.

As an example of improved fire safety obtainable with structure of thepresent invention, Underwriters Laboratory Tests reveal that the flamespread rate of the shingle of this invention incorporating thecatalytically reacted asphalt and chopped glass fibers at the exposededge can be reduced to 3 feet or less in 10 minutes, much within themaximum of 6-foot spread in 10 minutes for class A rated roofingshingles.

Although the method and apparatus is described above in relation to theproduction of asphalt shingles, it will be recognized that if desired,they are also readily adapted to production of a roll roofing product ofthe composite web of asphalt, glass fibers and granules. In thisrespect, the roll roofing product is usually desired to be more flexiblethan shingles in that the sheet must be rollable and is desirablyconformable to variations in contours of surfaces to which it isaffixed. Accordingly, the stiffness of the product web is desirablymodified for the less stiff condition. As indicated above, the spacingof webs across the thickness of the product, if reduced, will allow moreflexing with less stiffness, but additionally, the type of asphaltincorporated in the composite web can also be modified to provide agreater or lesser degree of stiffness. Thus, both the spacing of websand the type of asphalt are factors which will allow formation of an endproduct in accordance with predetermined needs.

In view of the penetrability of the coating grade asphalt in thecomposite structure of this invention, the asphalt can be selected forits weatherability, fire safety and stiffness, rather than being limitedto its compatibility with saturant asphalts of the conventional basefelt material, or to one which necessarily at least partially penetratessuch base felt. In conventional manner, the asphalt of the presentstructure is combined with a hot slate dust prior to application andcombination in the structure, but the degree of slate dust incorporatedin the asphalt is not limited to conventional amounts, therebypermitting a combination which as a mixture is more stable andselectable for weatherability. As a variation of the method of producingthe product of the present invention, an ordinary coating grade asphaltcan have a catalytic material mixed therein such as at the time ofaddition of the slate in order to incorporate a dormant catalytic actionin the structure. For example, /2% by weight of ferric chloride can beadded to the asphalt with the slate to provide the desired dormantreaction properties.

The presence of a glass fiber mat in the weathering zone of the productcauses the glass fibers to act as a reinforcement as well as a weatherbarrier for retention of the weathering components of the product.Studies indicate that the presence of the glass fibers reducesflowability as well as the coeflicient of expansion of the asphalt andconsequently increases its elastic properties in the weathering zone.Furthermore, whereas the actinic rays act to cause the surface asphaltto become more water soluble and thereby making the asphalt more subjectto being washed away with rain, snow, etc.; the presence of glass in theweathering zone imparts a stability against cracks and correspondingdegradation below the surface, thereby increasing the longevity of theproduct.

In use, the structure of the present invention improves considerably theweather resistance of asphalt shingles because the high quality asphaltis capable of being incorporated throughout its body and because of thestabilized condition imparted to the exposed surface by the network ofglass fibers immediately adjacent thereto. In addition, the productlends itself to tight securement to the surface which it is to protectby reason of the increased strength of the nailing zone incorporatingthe high strength additional reinforcing chopped glass fiber strands.

Still further, the fire safety of the product is enhanced byincorporation of the catalytically reacted asphalt which, because of itsdormant catalytic reaction, stands ready to be protectively activatedupon subjection to the high temperatures of flames. The dormantcatalytic reaction is in a sense a latent exothermic reaction triggeredby temperatures as low as 475 F. which produces a violent reactionresulting in a snufling action and consequent halt of flame spread. Theflame activated dormant reaction is believed to snuff the flame byspeeding up gassing, skinning and char-ring of the surface of theasphalt to entrap volatiles and also increasing the viscosity of thematerial toward solidification.

In addition to the high degree of retardation provided by the presenceof the catalytic asphalt, additional retardation of flame spread, and areduction of tendency toward support of combustion is provided by theglass fibers present in the chopped glass strand track at the exposededge of the Shingle which impairs flow of the asphalt and therebysimulates an increased viscosity of the asphalt at the edge of theshingle.

Whereas the structural product herein described is illustrated with twomats of glass fibers spaced from each other in the composite structure,it will be recognized that the principal improved weatheringcharacteristics of the structure result from the presence of the topmostmat of glass fibers in the product, whereas the bottom-most web or matof glass fibers adds stiffness and stability to the whole structure, aswell as a stronger nail-holding property. The bottom-most web has agreater degree of flexibility in selection and can in some instances beother material than a glass fiber mat. In this respect, the bottommostlayer can be selected specifically as a carrier for the combination ofmaterials deposited thereover, and accordingly may be different inconstruction and material from the top mat. It is preferable, however,that the bottom-most web be made of material of inert character such asglass fibers to promote the longevity thereof, since webs of organicmatter usually absorb moisture which shortens the life of the productand makes it less effective as a moisture protective sheet.

Although the invention is herein described in relation to the specificforms and embodiments, it will be understood from the foregoing thatmodifications and variations may be effected in the method, apparatus,and product of the invention without departing from the conceptsthereof, and we therefore contemplate by the appended claims to coverall such modifications as fall within the true spirit and scope of ourinvention.

We claim:

1. A weather resistant asphalt sheet for roofing, siding, shingles, andthe like, comprising a weathering grade asphalt extending throughout thethickness of said sheet, and a coextensive integrated porous mat ofmineral fibers fully impregnated by and enclosed within said asphalt,and at least one edge zone of said sheet containing mineral reinforcingfibers randomly arranged in greater con-' centration than the generalconcentration of fibers in said sheet.

2,. A roofing sheet comprising a weathering grade asphalt extendingthroughout the thickness of said sheet, and a coextensive integratedporous mat of mineral fibers fully impregnated by and enclosed withinsaid asphalt, said asphalt being a flame extinguishing asphalt and atleast one edge zone of said sheet containing mineral reinforcing fibersrandomly arranged in greater concentration than the generalconcentration of fibers in said sheet.

3. A roofing sheet like that of claim 2 wherein the reinforcing fibersconcentrated in the edge zone of said sheet comprise discontinuousdiscrete bundles of glass fibers.

4. A weather resistant sheet for roofing, siding, shingles and the likecomprising a weathering grade single asphalt matrix, a coextensiveporous mat of mineral fibers in which the fibers are interbonded inrandom arrangement throughout said Imat, said mat being fullyimpregnated and enclosed within said asphalt, said asphalt being an airblown asphalt catalytically processed having an incomplete reactiondormant at ordinary temperatures of use of said sheet but activatable atflame temperatures, said sheet having a flame barrier zone comprising agreater concentration of mineral reinforcing fibers in at least one edgeof said sheet, said sheet also having a reinforced longitudinal nailingzone aligned along a portion of said sheet where nailing is effected tosecure it to a surface to be protected, said nailing zone comprising arandom arrangement of mineral fibers in a concentration sufficient toimpart appreciable nail pull resistance to said sheet in said zone.

5. A weather resistant asphalt sheet like that of claim 4 wherein thefibers concentrated in the flame barrier and nailing zones comprisediscontinuous discrete bundles of glass fibers.

6. A weather resistant sheet for roofing, siding, shingles and the likecomprising a matrix of a single air blown asphalt which has beenprocessed by a partially completed catalytic reaction to accelerateoxidation of the asphalt and in which the incomplete portion of thereaction is dormant at ordinary temperatures of use of said sheet butactivatable at flame temperatures, a pair of parallelly spaced webs ofglass fibers separated fromeach other across the thickness of saidsheet, said webs being fully impregnated by and enclosed within saidmatrix material and being dimensionally coextensive with said sheet, anda flame barrier at least at one edge of said sheet comprising a greaterconcentration of .glass fibers distributed be tween said webs along azone immediately adjacent said edge.

7. A weather resistant sheet for roofing, siding, shingles and the like,comprising a weathering grade asphalt matrix in which the asphalt is anair blown asphalt in which oxidation has been catalytically acceleratedby a catalytic reaction and in which the reaction is partially completewith the remainder being dormant at ordinary temperatures of use of saidsheet but activatable at flame temperatures, a pair of individuallyintegrated glass fiber mats, said mats being c-oextensive in dimensionwith said sheet and being parallelly oriented and fully impregnated byand enclosed within said matrix material but in spaced relation acrossthe thickness of said sheet, each said mat comprising continuous glassfibers in the form of randomly distributed textile strands, said sheethaving a band of chopped glass fiber strands concentrated in an edgezone of said sheet to reinforce said edge against flame spread.

8. A weather resistant sheet for roofing, siding, shingles and the like,comprising a Weathering grade asphalt matrix in which the asphalt is anair blown asphalt in which oxidation has been catalytically acceleratedby a catalytic reaction and in which the reaction is partially completewith the remainder being dormant at ordinary temperatures of use of saidsheet but activatable at flame temperatures, a pair of individuallyintegrated glass fiber mats, said mats being coextensive in dimensionwith said sheet and bein-g parallelly oriented and fully impregnated byand enclosed within said matrix material but in spaced relation acrossthe thickness of said sheet, each said mat comprising randomly arrangedstrands of continuous glass fibers and randomly intermingleddiscontinuous individual glass fibers, said fibers being interbonded inintegrated relation in their respective mats by a thermosetting resinousbinding agent, the upper-most of said mats being disposed immediatelyadjacent the top-most surface of said matrix to reinforce said surface,and a layer of granules of mineral materials sheet in the top-mostreinforced surface of said sheet, and a flame barrier zone at one edgeof said sheet comprising a concentration of chopped glass fiber strandsdisposed immediately adjacent said edge within said matrix between saidmats.

9. A weather resistant sheet for roofing, siding, shingles and the like,comprising a weathering grade asphalt matrix in which the asphalt is anair blown asphalt in which oxidation has been catalytically acceleratedby a catalytic reaction and in which the reaction is partially completewith the remainder being dormant at ordinary temperatures of use of saidsheet but activatable at flame temperatures, a pair of individuallyintegrated glass fiber mats, said mats being coextensive in dimensionwith said sheet and being parallelly oriented and fully impregnated byand enclosed within said matrix material but in spaced relation acrossthe thickness of said sheet, each said mat comprising randomly arrangedstrands of continuous glass fibers and randomly intermingleddiscontinuous individual glass fibers, said fibers being interbonded inintegrated relation in their respective mats by a thermosetting resinousbinding agent, said mats being disposed immediately adjacent thetop-most and bottom-most surfaces of said mats respectively, and anailing zone located in a portion of the sheet in which nailing isgenerally efiected to secure the sheet to surfaces to be protectedcomprising chopped glass fiber strands distributed within said matrix insufficient concentration to appreciably increase the nail pullresistance of said sheet in said zone.

References Cited UNITED STATES PATENTS 2,555,401 6/1951 Fasold et a1.

2,658,000 11/ 1953 Sullivan et a1.

2,667,425 l/ 1954 Bierly.

2,718,479 9/ 1955 Bierly.

2,731,066 1/ 1956 Hogedobler et a1. 156-628 X 2,771,387 11/ 1956 Kleist161-202 X 3,095,339 6/1963 Craig 161-202 X 3,096,196 7/ 196 3 Bettoli eta1. 117-137 X 3,231,453 1/1-966 Smith 161-202 X EARL M. BERGERT, PrimaryExaminer.

T. R. SAVOIE, P. R. WYLIE, Assistant Examiners.

2. A ROOFING SHEET COMPRISING A WEATHERING GRADE ASPHALT EXTENDINGTHROUGHOUT THE THICKNESS OF SAID SHEET, AND A COEXTENSIVE INTEGRATEDPOROUS MAT OF MINERAL FIBERS FULLY IMPREGNATED BY AND ENCLOSED WITHINSAID ASPHALT, SAID ASPHALT BEING A FLAME EXTINGUISHING ASPHALT AND ATLEAST ONE EDGE ZONE OF SAID SHEET CONTAINING MINERAL REINFORCING FIBERSRANDOMLY ARRANGED IN GREATER CONCENTRATION THAN THE GENERALCONCENTRATION OF FIBERS IN SAID SHEET.